3.5.0¶

Backward Compatibility

We encourage you to use the latest version of the API. However, all previous versions remain available, so once you integrate, you can upgrade at your own pace.

Default port

This service uses port 11395 by default. You can change the port if needed. See Changing the HTTP port for instructions.

Security note

The Dracal Device Service HTTP server only accepts local connections to the REST JSON API. Remote connections are rejected for security reasons.

Get USB Devices¶

Request¶

GET http://localhost:11395/3.5.0/devices/usb

Returns information about all USB-connected devices, including their channels, configurations, and current readings.

Authentication: None required

Response Format: JSON

Query Parameters:

Parameter	Type	Default	Description
`pretty`	boolean	`false`	When `true`, the response JSON is indented (pretty-printed). Omitting the parameter or setting it to `false` returns minified JSON.

Response¶

devices: Dynamic data for each connected device instance
- Each device is keyed by its serial number (e.g., E22377)
- Contains real-time channel values, current connection details, and sensor measurements
- This data changes as devices report new measurements
products: Static product model definitions
- Describes the specifications and capabilities of each product model (e.g., VCP-BAR20-CAL/v1)
- Only includes models for currently connected devices
- Defines available channels, units, and device properties
- This data does not change and serves as a reference for device capabilities

Example¶

{
    "devices": {
        "E22377": {
            "channel_list": ["temperature"],
            "channels": {
                "temperature": {
                    "period_ms": 100,
                    "value": {
                        "magnitude": 121.5538101196289,
                        "timestamp": "2025-12-12T01:48:28.714Z",
                        "unit": "°C"
                    }
                }
            },
            "config": { "protocol": { "usb": true, "vcp": true } },
            "connections": {
                "usb": { "address": 20, "bus": 2, "product_id": "0504", "vendor_id": "289B" },
                "vcp": null
            },
            "info": {
                "firmware_version_major": 2,
                "firmware_version_minor": 4,
                "product": "VCP-RTD300-CAL",
                "serial": "E22377",
                "vendor": "Dracal technologies inc."
            },
            "model": "VCP-RTD300-CAL/v1"
        }
    },
    "products": {
        "VCP-RTD300-CAL/v1": {
            "channels": {
                "temperature": {
                    "description": "Temperature",
                    "details": { "virtual": false },
                    "label": "temperature",
                    "type": "Temperature",
                    "unit": "°C"
                }
            },
            "info": {
                "interfaces": { "usb": "tenkiusb", "vcp": "tenkivcp" },
                "name": "VCP-RTD300-CAL",
                "sku": "605048",
                "vendor": "Dracal technologies inc."
            },
            "model": "VCP-RTD300-CAL/v1"
        }
    }
}